When I post photographs of my aquarium on Twitter and elsewhere, I’m always surprised by the number of comments I receive about the mushroom corals.
I suspect it has a lot to do with the fact that most large marine aquariums don’t include any “mushroom corals” (Actinodiscus sp., Ricordea sp, etc). The choice has less to do with survivability than predation. Many marine fish consider soft-bodied, non-stinging mushroom corals a tasty (and defenseless) treat.
Fortunately, seahorses largely leave them alone, which means the mushrooms flourish in my tank. The largest ones are about 6″ in diameter when fully opened:
In the wild, mushroom corals live in shallow, well-lit waters where their zooxanthellae can get enough light for photosynthesis. The corals shrink at night and expand in daylight to increase the surface area for their symbiotic zooxanthellae.
These symbiotes give the mushroom coral its brilliant color and provide the coral itself with most of its energy. Mushrooms are capable of absorbing some nutrients from the water, but for the most part they “eat” what their symbiotes produce through photosynthesis and chemosynthesis.
Science-geekery aside, I love the mushroom corals for their floppy, soft appearance and beautiful colors. (For the record, they feel just as soft as they look, though they don’t much like being touched.) I have several varieties in the tank at present, and I’m always on the lookout for a new type or color to add to my collection.
Have you ever seen mushroom corals in the wild or in an aquarium? What’s your favorite coral? Let me know in the comments – I love to hear from you!